What is catarrh?
Doctors usually define catarrh as an excess of thick phlegm or mucus in one of the airways or cavities of the body. This most commonly occurs in the sinuses at the front of the face either side of the nose, but can also occur in the throat, ears or chest.
Catarrh is often a symptom of other conditions such as a cold, hay fever or other types of allergy-triggered problem, or mucous membranes.
Catarrh is caused by the body's immune system reacting to an infection or irritation. When this occurs, it sends white blood cells to the source of the infection or irritation, which then releases molecules that cause the mucous membranes to swell and produce mucus.
The swelling also narrows the cavity, resulting in further congestion and this catarrh can be clear and runny or thick and coloured. Some people have abnormally sensitive blood vessels that react to environmental triggers, such as cigarette smoke and pollution. This causes the affected blood vessels to swell in a similar way to an infection or allergic reaction and it is this swelling leads to congestion and catarrh; it is known as vasomotor rhinitis or non-allergic rhinitis. Cigarette smoke and pollution are common triggers for this, with others including perfume, alcohol, spicy food, changes in the weather and stress.
Most cases of catarrh do not require any medical attention as they usually clear up within a few days once your body fights off the underlying infection.